What would cause a spark plug to fail, TWICE?

[BIONICQ45]

Please see the link below for historicla data. (94Q45t)http://www.nicoclub.com/zerothread?id=28086

Any idea what would casue a spark plug to fail twice. The same cylinder, same symptons, the first failure was with an autolite plug and this failure is with the NGK. This is what the plug looks like after being removed from the engine.

Any help as to what casued this would greatly help me in deciding wheter to thromw money at it or not. Needlees to say, the electrode is still somewhere in the engine it was never found. Same thing happened in the aforementioned post with this car in summer of 2003. Thanks.
Modified by BIONICQ45 at 10:28 AM 2/24/2005

[metaverse3]

Take a peek here: http://xylem.syros.aegean.gr/~...s.htm

[DAEDALUS]

Good info there. It's one cylinder only, so you can eliminate anything systemic--timing, fuel, etc. I was going to suggest a clogged injector might be causing a lean condition. Do a compression test on the engine. If that cylinder's way low, then it's most likely vave-train related. If the compression is fine then perhaps it is the injector or carbon buildup.

[metaverse3]

Somethings to look out: Check out the ECU...see if there are any burnt pins... Check out the coil harness for the plug question..see if it talks back properly to the ECU (Continuity test) Check out the injector and the injector harness itself. See if it talks back to the ECU. Check out all the body grounds..especially the ones closer to the plenum area.. Check out the ignition module, and the CAM sensor module.. One thing you can rule out is the autolite plugs are not the problem from your previous disaster since the issue repeated itself with the NGK's... I hope you find the solution..I can feel your frustration..